An unusual case of urinary retention in a competitive gymnast.

Hydrocolpos is the accumulation of blood behind an imperforate hymen. Patients often present in early adolescence with cyclic abdominal pain. We present the case of an elite gymnast who, after 6 months of symptoms and a series of incorrect diagnoses, was diagnosed with hydrocolpos. It is likely that the patient's extraordinary training regimen contributed to the difficulty in diagnosis.